A huge market exists for disk drives for mass-market computing devices such as desktop computers and laptop computers, as well as small form factor (SFF) disk drives for use in mobile computing devices (e.g. personal digital assistants (PDAs), cell-phones, digital cameras, etc.). To be competitive, a disk drive should be relatively inexpensive and provide substantial capacity, rapid access to data, and reliable performance.
One example of a disk drive is a hard disk drive. A conventional hard disk drive includes a rotating magnetic disk, write and read heads that are suspended by a suspension arm adjacent to a surface of the rotating magnetic disk, and an actuator that swings the suspension arm to place the read and write heads over selected circular tracks on the rotating disk. The read and write heads are directly located on a slider that has an air bearing surface (ABS). The suspension arm biases the slider towards the surface of the disk, and when the disk rotates, air adjacent to the disk moves along with the surface of the disk. The slider flies over the surface of the disk on a cushion of the moving air.
When the slider rides on the air bearing, the write and read heads are employed for writing magnetic transitions to and reading magnetic transitions from the rotating disk. The read and write heads are connected to processing circuitry that operates according to a program to implement writing and reading functions.
Perpendicular magnetic recording (PMR) transducers are now being utilized to increase the data density of hard disk drives. Such perpendicular magnetic recording transducers record magnetic bits of a data in a direction that is perpendicular to the surface of the magnetic disk. A write head is used that generally includes a write pole having a relatively small cross section at the air bearing surface (ABS) and a return pole having a larger cross section at the ABS. A magnetic write coil induces a magnetic flux to be emitted from the write pole in a direction generally perpendicular to the plane of the magnetic disk.
Thus, a conventional magnetic recording head may include a PMR transducer residing on the slider. As previously described, the slider also includes an air-bearing surface (ABS) that faces the disk. A conventional PMR transducer may include a PMR pole and a top shield separated by a write gap. The top shield may also act as a pole during writing. The conventional PMR pole may be surrounded by an insulating layer. Similarly, the top shield may also be surrounded by another insulating layer.
Magnetic recording heads are typically constructed upon a wafer, with thousands of such recording heads being constructed on a single wafer. To form a slider, a wafer is cut into rows of sliders, and then this row of sliders is lapped to form the air bearing surface (ABS). This lapping surface determines critical dimensions such as the height of the PMR pole. Unfortunately, lapping processes are difficult to control, especially at the accuracy needed for very small recording heads. In particular, PMR pole fabrication is a very critical and challenging manufacturing step.
Accordingly, there is a need for a process in which the electronic lapping guide (ELG) and the PMR pole are fabricated simultaneously to allow for tight control of PMR pole height.